feat: make server own products

lib/views/bar/bar_screen_view.dart

@@ -90,6 +90,23 @@ class _BarScreenViewState extends State<BarScreenView> {
     }
   }
 
+  void _showSyncProblem({required String title, required String description}) {
+    final l10n = AppLocalizations.of(context);
+    showDialog<void>(
+      context: context,
+      builder: (dialogContext) => AlertDialog(
+        title: Text(title),
+        content: SelectableText(description),
+        actions: [
+          TextButton(
+            onPressed: () => Navigator.of(dialogContext).pop(),
+            child: Text(l10n.close),
+          ),
+        ],
+      ),
+    );
+  }
+
   void _logout() {
     context.read<PinLockViewModel>().lock();
     context.read<AdminPinViewModel>().lock();
@@ -142,6 +159,32 @@ class _BarScreenViewState extends State<BarScreenView> {
               icon: const Icon(Icons.cloud_off_rounded),
             ),
           ],
+          // A failing sync is otherwise invisible: the bar keeps working
+          // offline while nothing from the website arrives
+          if (context.watch<RemoteSyncViewModel>().lastError
+              case final error?) ...[
+            const SizedBox(width: 6),
+            // Offline is normal for a bar; anything else needs attention
+            if (context.watch<RemoteSyncViewModel>().isOffline)
+              IconButton(
+                tooltip: l10n.offline,
+                onPressed: () => _showSyncProblem(
+                  title: l10n.offline,
+                  description: l10n.offlineDescription,
+                ),
+                icon: const Icon(Icons.wifi_off_rounded),
+              )
+            else
+              IconButton(
+                tooltip: '${l10n.syncProblem}: $error',
+                color: Theme.of(context).colorScheme.error,
+                onPressed: () => _showSyncProblem(
+                  title: l10n.syncProblem,
+                  description: '${l10n.syncProblemDescription}\n\n$error',
+                ),
+                icon: const Icon(Icons.sync_problem_rounded),
+              ),
+          ],
           const SizedBox(width: 6),
           IconButton(
             tooltip: l10n.refresh,

lib/views/product_form_view.dart

@@ -12,6 +12,8 @@ import '../models/product.dart';
 import '../utils/money.dart';
 import '../utils/navigation.dart';
 import '../viewmodels/product_list_view_model.dart';
+import '../viewmodels/remote_sync_view_model.dart';
+import 'widgets/managed_on_website_notice.dart';
 
 class ProductFormView extends StatefulWidget {
   final String? productId;
@@ -313,6 +315,9 @@ class _ProductFormViewState extends State<ProductFormView> {
   Widget build(BuildContext context) {
     final l10n = AppLocalizations.of(context);
     final title = widget.isEditing ? l10n.editProduct : l10n.addProduct;
+    // A paired tablet gets its products from the website: only the stock and
+    // the picture are changed here
+    final managedOnWebsite = context.watch<RemoteSyncViewModel>().isConfigured;
 
     return Scaffold(
       appBar: AppBar(
@@ -322,7 +327,7 @@ class _ProductFormViewState extends State<ProductFormView> {
           onPressed: _leaveProductForm,
         ),
         actions: [
-          if (widget.isEditing)
+          if (widget.isEditing && !managedOnWebsite)
             IconButton(
               onPressed: _delete,
               icon: const Icon(Icons.delete_outline),
@@ -342,10 +347,15 @@ class _ProductFormViewState extends State<ProductFormView> {
                         ScrollViewKeyboardDismissBehavior.onDrag,
                     padding: const EdgeInsets.all(24),
                     children: [
+                      if (managedOnWebsite) ...[
+                        const ManagedOnWebsiteNotice(),
+                        const SizedBox(height: 16),
+                      ],
                       _buildImagePicker(context),
                       const SizedBox(height: 24),
                       TextFormField(
                         controller: _nameController,
+                        enabled: !managedOnWebsite,
                         decoration: InputDecoration(
                           labelText: l10n.productName,
                           border: OutlineInputBorder(),
@@ -366,6 +376,7 @@ class _ProductFormViewState extends State<ProductFormView> {
                             builder: (context, constraints) {
                               return DropdownMenu<String>(
                                 width: constraints.maxWidth,
+                                enabled: !managedOnWebsite,
                                 initialSelection: _selectedCategory,
                                 enableFilter: true,
                                 enableSearch: true,
@@ -395,6 +406,7 @@ class _ProductFormViewState extends State<ProductFormView> {
                       const SizedBox(height: 16),
                       TextFormField(
                         controller: _priceController,
+                        enabled: !managedOnWebsite,
                         decoration: InputDecoration(
                           labelText: l10n.price,
                           prefixText: '€ ',
@@ -455,6 +467,7 @@ class _ProductFormViewState extends State<ProductFormView> {
                         const SizedBox(height: 16),
                         TextFormField(
                           controller: _lowStockController,
+                          enabled: !managedOnWebsite,
                           decoration: InputDecoration(
                             labelText: l10n.lowStockThreshold,
                             border: OutlineInputBorder(),

lib/views/product_list_view.dart

@@ -9,6 +9,8 @@ import '../l10n/app_localizations_helpers.dart';
 import '../utils/money.dart';
 import '../utils/navigation.dart';
 import '../viewmodels/product_list_view_model.dart';
+import '../viewmodels/remote_sync_view_model.dart';
+import 'widgets/managed_on_website_notice.dart';
 
 class ProductListView extends StatefulWidget {
   const ProductListView({super.key});
@@ -31,6 +33,8 @@ class _ProductListViewState extends State<ProductListView> {
   Widget build(BuildContext context) {
     final viewModel = context.watch<ProductListViewModel>();
     final l10n = AppLocalizations.of(context);
+    // A paired tablet gets its products from the website
+    final managedOnWebsite = context.watch<RemoteSyncViewModel>().isConfigured;
 
     return Scaffold(
       appBar: AppBar(
@@ -41,11 +45,13 @@ class _ProductListViewState extends State<ProductListView> {
         title: Text(l10n.products),
       ),
       resizeToAvoidBottomInset: false,
-      floatingActionButton: FloatingActionButton.extended(
-        onPressed: () => context.push('/products/new'),
-        icon: const Icon(Icons.add),
-        label: Text(l10n.addProduct),
-      ),
+      floatingActionButton: managedOnWebsite
+          ? null
+          : FloatingActionButton.extended(
+              onPressed: () => context.push('/products/new'),
+              icon: const Icon(Icons.add),
+              label: Text(l10n.addProduct),
+            ),
       body: Builder(
         builder: (context) {
           if (viewModel.isLoading) {
@@ -56,16 +62,19 @@ class _ProductListViewState extends State<ProductListView> {
             return Center(child: Text(l10n.errorText(viewModel.loadError)));
           }
 
-          if (viewModel.products.isEmpty) {
+          if (viewModel.products.isEmpty && !managedOnWebsite) {
             return Center(child: Text(l10n.noProductsYet));
           }
 
+          // The notice takes the first row
+          final offset = managedOnWebsite ? 1 : 0;
           return ListView.separated(
             padding: const EdgeInsets.all(16),
-            itemCount: viewModel.products.length,
+            itemCount: viewModel.products.length + offset,
             separatorBuilder: (_, _) => const SizedBox(height: 8),
             itemBuilder: (context, index) {
-              final product = viewModel.products[index];
+              if (index < offset) return const ManagedOnWebsiteNotice();
+              final product = viewModel.products[index - offset];
 
               return Card(
                 child: ListTile(

lib/views/widgets/managed_on_website_notice.dart

@@ -0,0 +1,24 @@
+import 'package:flutter/material.dart';
+
+import '../../l10n/app_localizations.dart';
+
+/// Tells that the products of a paired tablet are managed on the website.
+class ManagedOnWebsiteNotice extends StatelessWidget {
+  const ManagedOnWebsiteNotice({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    final colors = Theme.of(context).colorScheme;
+
+    return Card(
+      color: colors.secondaryContainer,
+      child: ListTile(
+        leading: Icon(Icons.language, color: colors.onSecondaryContainer),
+        title: Text(
+          AppLocalizations.of(context).productsManagedOnWebsite,
+          style: TextStyle(color: colors.onSecondaryContainer),
+        ),
+      ),
+    );
+  }
+}